Cap-free neck end for a filler neck

ABSTRACT

A cap-free closable neck end for a filler neck of a tank of a motor vehicle, the cap-free closeable neck including an upper entry space forming an insertion region for a fuel nozzle and being surrounded by a side wall, a lower sealing flap arranged in the upper entry space and closing mechanism arranged above the lower sealing flap. The closing mechanism includes an upper filling opening and an upper cover, which in a closed state at least partially covers the upper filling opening and being embodied in such a manner that the upper cover is displaced by inserting an outlet pipe of a fuel nozzle into the upper entry space for releasing the upper filling opening so as to allow for the insertion of the outlet pipe through the upper filing opening and the lower sealing flap. When used for forming a protection against a filling with unsuitable fuel, the upper cover, in its closed state, is blocked by a locking element and wherein the locking element is embodied in such a manner that it is unlocked as a function of a type-specific shape of the outlet pipe of the fuel nozzle, only when the tank is filled with suitable fuel.

CROSS REFERENCE TO RELATED APPLICATION

This Application is a Divisional of U.S. patent application Ser. No.11/885,446, filed Aug. 29, 2007, which is a National Stage of PCTInternational Application No. PCT/EP2006/050864, filed Feb. 10, 2006,and claims priority of German Patent Application No. 20 2005 002 223.3,filed on Feb. 10, 2005 and European Patent Application No. 05110674.8,filed Nov. 12, 2005. The disclosures of the aforementioned applicationsare incorporated herein in their entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a neck end for a filler neck of a tankof a motor vehicle, in particular a neck end which can be closed withouta cap having an entry space, which is particularly but not necessarilydesigned as a pipe section having a funnel or pipe-like wall, whereinthe entry space can have a continuous or changing cross section of anyshape. In the following, the entry space will be identified in thisdescription as a pipe section, without this being associated with alimitation to a certain geometry.

2. Description of the Related Art

In the pipe section, the neck end has a lower sealing flap and, abovethe lower sealing flap, a closing mechanism, which has an upper fillingopening and at least one upper cover, which at least partially coversthe upper filling opening in its closed state. The closing mechanism isthereby embodied in such a manner that the upper cover is displaced byinserting an outlet pipe of a fuel nozzle into the pipe section forreleasing the upper filling opening so as to allow for the insertion ofthe outlet pipe through the upper filling opening and the lower sealingflap. Almost throughout the world, the fuel nozzles thereby have adifferent pipe diameter for diesel fuels and gasoline.

Neck ends of this type are known from DE 203 09 799.8 U1. In this neckend, the neck is closed via two flaps, which are arranged on top of oneanother in the neck and which are held against a sealing surface by theforce of, in each case, a closing spring. The two caps are presseddownward by inserting the outlet pipe of a fuel nozzle or of a spout ofa jerry can, thus resulting in a continuous opening.

Even though these closures provide for a good seal, even without anadditional tank cap, it would still be desired if they could be furtherimproved and if they additionally had a protection against improperfueling. Particularly in the case of modern engines, it is increasinglyimportant to keep in mind safe fuel grades due to the fact that, forexample, modern injection systems of a common-rail diesel injection arelubricated via the lubricant content of the diesel fuel and can sustainheavy damages after being operated with a gasoline for only a shortoperating time.

SUMMARY AND OBJECTS OF THE INVENTION

It is thus an object of the present invention to create a neck end,which can be produced as simply as possible and which offers to minimizethe danger or an improper fueling, by using a closure, which is as safeas possible.

According to the present invention, this object is solved in that, forthe purpose of creating a protection against a filling with unsuitablefuel, the upper cover in its closed state is blocked by at least onelocking element and in that the locking element is embodied in such amanner that it can be unlocked as a function of the shape of the outletpipe of the fuel nozzle, only in response to a fueling with suitablefuel.

Even though the present invention does not yet make every improperfueling impossible, the risk, however, is clearly minimized. It iscommon throughout the world that lead free gasoline is pumped by fuelnozzles, which have a smaller diameter of the lower end of the outletpipe than diesel fuels. This fact can thus be used according to thepresent invention for avoiding an unlocking of the neck end in the eventthat the incorrect fuel nozzle is used and it is as least possible toprevent a fueling of a vehicle comprising a diesel engine with gasoline.

Provided that the petroleum trade is to use further fuel nozzle modelsin the future, a further increase of the error protection will obviouslybecome possible. In an ideal case, each attempt of an improper fuelingcan already be prevented if a type-specific diameter of the outlet pipeis used, which does not only contribute to the prevention of unnecessaryrepair costs, but also to the relief of impacts on the environment, inthat deficiencies must then no longer be disposed of. Car rentalcompanies can then also trust that the vehicles are no longerdeliberately or carelessly fueled with unsuitable fuel, so as to savecosts when the cars are being returned, for example, or because thedriver is not able to speak the respective language of the country andreaches for the wrong fuel nozzle out of ignorance.

When the term “cap-free” is used in the context of this application,this does obviously not refer to the fact that the filler neck does nothave an internal cap. Instead, what is meant here is that it is nolonger necessary to use a conventional tank cap in the traditionalsense, but that one could possibly be used for safety reasons. In thecontext of this application, the term “pipe section” is to describe theinflow region of the neck, which obviously does not need to have acylindrical cross section, but can have any cross section, which iseither constant or which changes across the depth of the neck.Furthermore, the range of application of the present invention is not tobe limited to the tank cap, even though the application will bedescribed below as the preferred use. On principle, a use is possiblefor all storage tanks inside and outside of vehicle technology, in thecontext of the motor vehicle in particular also in the region of thefiller neck for the engine or transmission oil.

The neck end of the present invention is affected by the possibility oflocking the upper filling opening and to be able to override thislocking only if the “correct” fuel nozzle is used. This can occur inmanifold ways. One possibility is, for example, that the fuel nozzlepushes two clamping jaws, which are located opposite one another,sidewards, said clamping jaws, in turn, locking a pivot plate, whichcovers or closes the upper filling opening from below. The followingcases are possible with the fueling systems, which are presently mostfrequently used:

1. When attempting to wrongly fuel diesel fuel into a vehicle with anOtto engine, the fuel nozzle of the diesel filling pump will have alarger diameter than the “expected” fuel nozzle of the filling pump forgasoline. In this case, the fuel nozzle is too large to be inserted intothe area of operation of the filler neck; it can thus not push theclamping jaws outwards and the operator will recognize the error in thatthe upper cover cannot be opened and the fuel nozzle cannot be insertedinto the filler neck.

2. When attempting to wrongly fuel gasoline into a vehicle with a dieselengine, the fuel nozzle of the filling pump for the gasoline will have asmaller diameter than the “expected” fuel nozzle of the diesel fillingpump. The fuel nozzle is now not thick enough and will thus not be ableto simultaneously touch both clamping jaws or to even press them apart.Instead, maximally a single clamping jaw is detected so that the lockingcan then also not be disconnected herewith, even if in this case thefree end of the fuel nozzle can be inserted into the area of operation.

An advantageous embodiment of the present invention provides an inclinedplane having a laterally protruding edge as the area of the operation,wherein the outlet pipe can slide on the inclined plane. This inclinedplane represents a sliding surface for the fuel nozzle, which isinclined at an angle α relative to the longitudinal axis of the pipesection of the filler neck, which protects the upper filling openingagainst the release of the locking

The user initially places the fuel nozzle slightly next to the actualfilling opening at the top of the sliding surface and then allows forthe outlet pipe to slide along the sliding surface. This movement canthen drive a mechanism, which causes the unlocking of the closingmechanism. This can occur, as already described above, by pressing apartthe clamping jaws, wherein a fuel nozzle, which is too large, cannot beinserted between the raised edge of the inclined plane and would thusslide on the edge, but would thus not come into contact with theclamping jaws.

However, due to this lateral load on the outer jacket surface of theoutlet pipe, the fuel nozzle can be subjected to wear, because the fuelnozzle is typically made of aluminum and is thus only slightlywear-resistant.

Another embodiment thus presses the locking elements downward against areturn spring. This causes considerably less damage to the material andfurthermore allows for the use of springs, which are longer and betterguided. Here, a raised edge can also prevent a fuel nozzle, which is toolarge, from pressing down the locking elements, provided that thisshould be necessary. A further advantage of the raised edge lies inprotecting the locking elements against being pressed openunintentionally, for instance as a result of an accident.

When placing the outlet pipe on the inclined plane, two lockingelements, which are arranged opposite one another, are pressed down, forexample, then preferably causing a sliding of the outlet pipe on thesliding surface only at that point.

For this purpose, provision is made for a sliding element, which isdetermined by the locking and which can be unlocked by the describedmechanism. The sliding element is mounted next to and above the slidingsurface so as to be laterally displaceable. This sliding element islaterally displaced after the locking elements have been depressed bythe outlet pipe, wherein the outlet pipe of the fuel nozzle togetherwith the further downward movement is also further pushed to the sidethrough this, until the sliding element completely releases the upperfilling opening. Consecutively, the outlet pipe can then be insertedinto the pipe section and can depress the lower sealing flap at thatlocation.

Further features of the neck end as claimed in the present invention arehigh and low pressure valves. Provided that the upper cover is alsoembodied so as to seal, the lower sealing flap and this upper cover caneffect a corresponding pressure compensation upon the occurrence ofcritical pressures, caused by heat expansion, for instance, or theremoval of fuel from the tank at the engine side.

A water channel, which removes water or condensate ingress, canfurthermore be arranged above the lower sealing flap, so that the wateror condensate ingress does not reach the tank during the next opening ofthe lower sealing flap.

A further aspect of the present invention, which can also be applieddetached from the claimed cap-free filler neck, is the use of a neckend, which can be attached to an already known neck. According toexperience, it is difficult to carry out the basic change of the neckduring a running vehicle production for commercial-organizationalreasons. If, for example, an already constructed system is to beconverted to a cap-free fueling during the production, the neck end canbe attached to an interface of the neck.

However, the driver is not to be able to remove the neck end by himself.Instead, this should be left to the expert repair shop. To prevent anunauthorized removal, the neck end can thus be provided with a retainer,which can easily be attached to the filler neck, but which can only bedetached with the destruction or without destruction by using a specialtool. Such a retainer can be formed, for example, by spring elements,which engage in recesses according to the type of a snap ring during orafter screwing the neck end onto the conventional end piece of a fillerneck and which can only be retracted by a tool, which can be inserted,for example, between the wall of the filler neck and the neck end,wherein the used tool can then contract two ends of the open snap ringand thus overrides the positive contact.

A further feature of the present invention, which can also be usedindependent on the concrete embodiment of the neck end as describedabove, can be that the neck end and the neck form two separatecomponents, which can be connected with one another via a specialconnection, so that it is possible to replace the neck end without thefiller neck itself. This has the special advantage that, afteraccommodating a larger amount of mechanical parts, it may be possiblethat repair may be necessary more often in the region of the neck endand this can be taken care of without replacing the entire neck.

If the neck end, for example, has the above-described locking flaps,these mechanical parts could be damaged. The neck pipe itself istypically a plate or a plastic pipe. A plastic pipe, in particular, isoften also fixedly welded with a plastic tank. At any rate, thereplacement of the entire filler neck up to the tank is comparativelyextensive, because access to this region is difficult and can only bemade from the underside of the vehicle. Depending on the vehicleconstruction, the tank can also be accessible only via the interior withthe removal of further parts, so that there is a necessity to be able torepair a neck end in an easier and simpler manner than by replacing theentire filler neck.

For this purpose, the filler neck has a removable connection, similar tothe case of the neck end, which can be retrofitted, for standard bayonetor screw closures. The filler neck includes the neck end and the actualneck pipe, which is guided to the tank and which can there be connectedwith the tank so as to be removable or fixed. The connection betweenneck end and neck pipe now occurs via a connection, which is designed insuch a manner that it can preferably only be detached via a tool. If itis not desired to exclude a possibility for misuse, the connection canalso be designed so as to be capable of being disconnected in a simplemanner.

A connection, which can be disconnected via a tool, can be formed byresilient locking elements. These locking elements can also be designedhere according to the type of a snap ring. The neck end can thus be slidonto the neck pipe, wherein the snap ring can be arranged between theinner wall of the neck end and the outer wall of the neck. An additionalseal, for instance in the shape of an O-ring, can provide the requiredimpermeability. The ends of the snap ring can then be pressed togetheror apart by a tool.

A further possibility lies in that the resilient elements are arrangedin the interior of the neck end and that they engage in locking recessesin the inner wall of the neck pipe through recesses in the wall of theneck end. These resilient elements can then be gripped from the insidevia the tool and can be retracted inwards so as to be able to detach theneck end. Needless to say, all other conventional twisting tools arealso possible.

Finally, it is also possible that the neck end is initially connectedwith the neck pipe in one piece and in a fixed manner and that aremovable neck end is attached only in case repair is necessary afterremoval, for example by sawing off the defective neck end. For thispurpose, the neck pipe can already have corresponding provisions so thata replacement part can be placed according to the above-mentionedprinciples after removing the available neck end.

A further preferred embodiment of the present invention has anadditional protection against leakiness in case of an accident. Thisprotection can also be used independent on the specific embodiment ofthe neck end, as described above and as claimed in the claims. Only thefact that a double closure via an upper and a lower sealing flap ispresent is necessary for this.

In case of an accident, there is always the possibility that the neckend is impinged on with an inadmissibly high shearing force, as a resultof a deforming edge or an impinging object. In this case, the shearingforce is introduced into the neck, which, without special provisions,could break at a location, which cannot be controlled. In particular dueto the fact that, on the one hand, the neck geometry is substantiallyadapted to the shape of the undercarriage and to the position of theneck end, and on the other hand, to the fuel container, a weak spot willnot occur anywhere during the course of the neck pipe, as a result of achange of the geometry, which could possibly appear as a break.

To prevent a lower breaking of the neck pipe, as this could possiblylead to a fuel escape, the neck pipe is made of a suitable material,which is break-proof on the one hand and which has a sufficientflexibility on the other hand for withstanding a certainaccident-related degree of deformation, while being free from leakage.An even better protection can be achieved in that a predeterminedbreaking point is arranged between the upper and the lower sealing flap.This predetermined breaking point causes an ultimate moment lead intothe wall of the neck end to cause the upper part of the neck end tobreak, without affecting the lower part of the neck end or even the neckpipe, which is located therebelow. In this case, the lower sealing flapis still available, which sufficiently seals the neck end so as toprevent a fuel escape even with a vehicle, which was involved in anaccident.

Preferably, provision can be made for the predetermined breaking pointby a depression, which is arranged in the wall of the neck end betweenthe upper and lower sealing flap. Said predetermined breaking point cansimply be impressed into the plastic material of the neck end or canalready be provided during production. To intensify the effect of thepredetermined breaking point, provision can be made for additionalmaterial reinforcements above and below the depression.

In the alternative, the neck end can also be embodied so as to includetwo pieces so that an upper part having the upper sealing flap isinserted into a lower part having the lower sealing flap, wherein theconnection assembly is sealed via a seal, for example an O-ring. Theupper and the lower part of the neck end then each have a pipe-shapedbasic body, being inserted into one another, by inclusion of the O-ring.

Here, the predetermined breaking point can be realized in that theconnection assembly can be severed. To prevent this from happening bymistake, the connection assembly is preferably embodied in such a mannerthat the upper and the lower part of the neck end are inseparably wedgedafter assembly of the neck end via snap-in pins, wherein the snap-inpins can break in response to an occurrence of the critical breakingforce and the upper part can be detached. In this embodiment, theoverlap region of the upper and the lower part of the neck can be keptquite small, so as to ensure a safe severing in the region of thepredetermined breaking point in response to the appearance of theshearing force.

Additional features and advantages of the invention result from thebelow description of a preferred exemplary embodiment of the presentinvention by the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a side view in section onto an embodiment of a neck end inaccordance with the present invention;

FIG. 2 shows the detail “Z” from FIG. 1;

FIG. 3 shows a second embodiment of a neck end in a top view inaccordance with the present invention;

FIG. 4 shows a third embodiment of a neck end having a predeterminedbreaking point in a side view in section in accordance with the presentinvention;

FIG. 5 shows an embodiment of a filler neck including the upper part ofa neck pipe and a neck end fastened thereon in accordance with thepresent invention; and

FIG. 6 shows an embodiment of the upper part of a neck end havinglocking pins for locking via central locking system in accordance withthe present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S) OF THE INVENTION

FIG. 1 illustrates a side view of an exemplary embodiment of the presentinvention, which will be described below, without limiting the presentinvention or the scope of protection of the instant application to thisconcrete embodiment.

The neck end illustrated in FIG. 1 is formed by a pipe section, thecross section of which initially widens in a conical manner in thedirection of the opening. Provision is made below the widened sectionfor the lower sealing flap 2, which seals the neck. For this purpose,the sealing flap is placed against a sealing surface (not illustratedherein) via a spring. Furthermore, the neck end encompasses the high andlow pressure valves, which are reflected as detail “Z” in FIG. 2 in anenlarged illustration as well as a water discharge, which is also notillustrated here, via which the water ingress can be drained.

Initially, provision is made in the upper region for the upper fillingopening 5, through which the outlet pipe 4 of the fuel nozzle can beinserted into the neck, which then opens the lower sealing flap 2 inresponse to a further ingress. A closing mechanism 3, which prevents aninsertion of the fuel nozzle without opening the closing mechanism 3, isarranged above the upper filling opening 5.

To now minimize or, if possible, prevent improper fueling, the closingmechanism 3 is to be capable of being opened only if the “correct” fuelnozzle, that is the fuel nozzle for filling suitable fuel, is placed.

For this purpose, a ring element 14 is inserted into the upper necksection of the pipe section 1, in which, in turn, a sliding element 30is guided at right angles to the neck axis in a displaceable manner. Thesliding element 30 is U-shaped, wherein it could likewise also beembodied all around as a closed element. Substantial is here only thatit has an outlet, through which the outlet pipe 4 can be inserted.

Locking elements 7, which engage in recesses in the sliding element 30in the upper region in a positive manner, are now depressed by theinserted outlet pipe 4. As a result of being depressed, the lockingelements 7 now disengage, the sliding element 30 is thus released andcan then be displaced in lateral direction.

Below the sliding element 30, an inclined plane is embodied as a slidingsurface 10, which is incorporated into the inner jacket surface of thering element 14. The sliding surface 10 is inclined at an angle αrelative to the neck axis of the pipe section 1 and causes a lateraldisplacement of the outlet pipe 10, which is inserted through thesliding element 30 if it is further inserted into the pipe section 1.

As a result of the lateral displacement, the outlet pipe 4 is nowpressed against the sliding element, which, in turn, causes a lateraldisplacement of the sliding element, until the region above the upperfilling opening is completely released for the insertion of the fuelnozzle. However, this unlocking and the subsequent displacement of thesliding element is only possible, if both locking elements 7, which arelocated opposite one another, are depressed by the lower edge of thefuel nozzle. If the fuel nozzle is not large enough, because thediameter of the outlet pipe 10 is too small, either none or only onelocking element 7 can be depressed, which, however, does not overridethe locking.

The sliding element is embodied in such a manner that it holds thelocking elements 7 downwards after the displacement, even if the loweredge of the fuel nozzle is moved laterally towards the right and is nolonger arranged above the locking elements 7. In this stage, the leftregion of the sliding element depresses the locking elements 7.

As an alternative to the two locking elements 7, further lockingelements could certainly also be used. It is only important that theunsuitable fuel type is administered via a fuel nozzle, which cannotactuate all of the locking elements 7. The depression of the lockingelements 7 has the special advantage that a wear of the fuel nozzle islargely excluded. In particular, lateral grooves cannot be introduced.

In the illustrated preferred embodiment, the locking elements 7 are eachformed by a locking pin, which engages in a positive manner into arecess in the upper cover 6. Said locking pin can be relocated downwardthrough the free end of the outlet pipe 4 against the force of a safetyspring 9. In so doing, the locking pin “unlatches” out of the recess inthe sliding element, which is being used as the upper cover.

In terms of this protection feature, the sliding element has a blockingzone, also known as a locking region, which means nothing more than thatit is arranged in closing position with a part of its body above theupper filling opening. The upper filling opening is then released onlyby the lateral displacement. The inclined sliding surface 10 has, inparticular, an inclined position relative to the axis of the pipesection 1 of from 20° to 80°, preferably from 35° to 55° and, as isillustrated here, more preferably of 45°.

Preferably, as is illustrated here, the closing mechanism is protectedvia a cover cap 11, which has a long hole for inserting the outlet pipe4, wherein the width of the long hole is slightly larger than thediameter of the outlet pipe 4 and the length of the long holesubstantially corresponds to the course of displacement of the slidingelement.

Provision is made here above the upper filling opening 5 for anadditional closing cap 12, which causes an anti-theft protection and afurther seal. For this purpose, the additional closing cap 12 isflexibly arranged on the sliding element and is displaced therewith. Atthe opposite side, it engages into a locking groove 13, which fixes theadditional closing cap 12 in its closed state. After removing the fuelnozzle, a return spring resets the flap 12 so that it can again engagein the locking groove 13 when the sliding element glides back.

In addition, the locking elements can be blocked via the central lockingsystem of the motor vehicle in such a manner that an unlocking is onlypossible if the central locking system is in the opening position. Forthis purpose, an electrically driven pin can prevent a movement of thesliding element, as is already the case with the protection of knownfuel filler doors, for example.

Finally, the neck end can be designed as an independent component forconnection with a known pipe connection or it can naturally also beformed directly into the neck of a tank. If it is an independentcomponent, it can be welded with the pipe section, which is mostly madeof plastic, or it can also be connected with the neck via the standardconnection/common fastening, which was used for the placement andfastening of a tank cap until now. It is well known in the art that sucha standard connection/common fastening would involve a threaded memberso that the neck end has a structure so as to be screwed onto thethreaded member. This has the special advantage that no change must bemade to the neck, if a vehicle is retrofitted to a cap-free fuelling.Preferably, the neck then has a removal protection, which can only bedetached by a tool, so that the driver himself can no longer manipulatethe tank closure.

FIG. 2 reproduces the lower sealing flap 2 in an enlarged illustration.The sealing flap 2 includes a pivot flap, which is arranged on a pivotbearing 15 and which is pressed against a storage edge in the pipesection 1 of the filler neck, including a seal 16 by the force of aclosing spring.

In the upper part, the sealing flap 2 has a pressure region, againstwhich the lower edge of the fuel nozzle can support itself. For thepurpose of centering the fuel nozzle, provision is made in the centerregion for a ridge, which protrudes upwards. The pressure region has atleast one outlet via which pressures can enter into the interior of thesealing flap 2. The illustrated example has two outlets 17.

In the lower region, the sealing flap 2 is provided with a high pressurebypass 19 and with a low pressure bypass 18, via which low and highpressures, respectively, can be compensated. All types of pressurevalves can be used for this purpose, wherein a spring-loaded camfollower is used in the illustrated exemplary embodiment, which supportsitself with an upper rim on one side of the bottom of the sealing flapand which is guided through a passage opening in the bottom of thesealing flap with a handle body, while leaving a breathing opening,wherein a spring is clamped between the free end of the handle body andthe bottom of the sealing flap. Here, the sealing occurs via the rim,which lifts from the bottom of the sealing flap after overcoming thespring force for the actuation of the respective bypass.

FIG. 3 illustrates a further embodiment of the neck end, which, in placeof locking elements 7, which are to be pressed downward, has lockingelements 7, which are laterally displaced by the end of the outlet pipe4 of the fuel nozzle. As in the case of the illustrated exemplaryembodiment, this displacement can occur directly by contact with thefuel nozzle, but it is also possible that the fuel nozzle can beinserted into a (non-illustrated) sliding body, which must be pusheddownwards together with the end of the outlet pipe 4. This sliding bodythen has a passage opening, through which the fuel nozzle can beinserted into the neck end once the end position has been reached.

FIG. 4 illustrates a neck end including a predetermined breaking point20, which, in the instant case, is formed by a depression, which isimpressed into the neck wall from the outside, thus resulting here in aweakening of the material. The purpose of this predetermined breakingpoint 20 is that, in the event of an inadmissible shearing force, theupper region of the neck end can break, while maintaining the sealeffect of the lower sealing flap 2 and the seal effect of the fillerneck thus substantially maintains, in spite of an inadmissibly highshearing force.

FIG. 5 shows the connection of a neck end having a pipe connection 23 ofa tank neck system, which is embodied in two pieces, wherein the neckend, however, can only be detached from the pipe connection 23 with thedestruction of the connection element or by means of a tool.

For the connection with the pipe connection 23, the neck end is pushedonto the pipe connection, wherein resilient holding elements 22 engageinto recesses of the pipe connection 23 in such a manner that adetaching is only possible with the destruction of the resilient holdingedges 24 or by inserting the tool. For the positive connection with theends, the engaged resilient holding elements 22 engage around holdingedges 24 of the pipe connection 23, so that the neck end is held tight.A seal (which is not illustrated here) seals the connection.

FIG. 6 illustrates a further embodiment of the filler neck whereprovision is made for a locking pin 21, which can be actuated via theswitching elements of a central locking system of the motor vehicle.This bolt-shaped locking pin 21 incorporates the neck end into thecentral locking system of the motor vehicle, in that it pushes againstthe upper cover 6, when in its closed state, so that said upper cover 6cannot be displaced. As a result, the additional closing cap 12, whichforms the upper sealing flap in the illustrated exemplary embodiment,cannot be disengaged from the locking groove 13, the upper sealing flapin the form of the closing cap 12 thus remaining closed, provided thatthe locking pin 21 remains depressed. The locking pin 21 is retractedonly in response to an opening of the central locking system, so thatthe fueling system is released by means of the central locking system.

The locking pin 21 also permits further additional functions. In theevent of a running engine, for example, the vehicle electronics canautomatically place the locking pin against the upper cover 6, so that afueling of the vehicle is only possible if the engine is turned off. Thefueling of a vehicle while an external heater, in particular anauxiliary heating system, is turned on is also prevented via the samefunction. This increases the protection against careless disregard ofregulations by the driver.

Furthermore, the function of the locking pin 21 can also be coupled tocrash sensors or other elements of the control of the driving dynamicsso that the neck end is once again closed in time prior to the vehiclebeing involved in an accident so that the inherently impossible casethat the upper cover 6 is pushed away by a foreign object or by adeforming chassis edge can additionally be prevented.

It goes without saying that the locking pin 21 can also be arranged atany other position of the cap. It is even possible that the locking pinis embodied in a disk-shaped manner and that it can be moved in lateraldirection in front of the pipe opening as an additional sealing flap.

The locking of a pivot flap, which is typically provided in a vehiclefor covering the tank neck can now become dispensable by the locking pin21. On the one hand, this enables again the previously conducted designof the chassis having a visible neck end, where, for example the uppercover can be made of stainless steel for creating an interesting opticaleffect and furthermore saves the displacement of the locking pin 21against an area of sheet metal of the chassis, which is locatedrelatively far outside, which could possibly be damaged through this, ifperhaps the pivot flap is not completely closed and the locking pin 21is not displaced into the provided opening, but instead pushes againstthe edge of the opening.

In connection with the predetermined breaking point 20, provision canalso be made for the locking pin 21 in the region of the lower sealingflap 2, either as a single locking pin 21 or as an additional lockingpin 21. This would have the advantage that the locking will not beoverridden by breaking off the upper neck end. This could not beoverridden again by breaking off the locked part, particularly if alocking is to take place automatically in connection with the crashsensor system.

It is necessary for the central locking system function of the neck endthat provision is made for a locking pin 21 that fixes one of thepivotable sealing flaps regarding to their pivoting movement, or thatblocks the movability of the one longitudinally movable functionalregion of the neck end was blocked, provided that the accessibility intothe interior of the pipe connection 23 is provided by the longitudinalmovability.

The provision of the predetermined breaking point 20 as well as thecomplex central locking system and the embodiment of the filler neck asa two-piece component comprising an upper neck end and lower pipe neck,which is connected therewith only with the destruction of the connectionis presently considered to be an independent invention complex, which isnot required to be in connection with the embodiment of the neck end inthe region of the upper and the lower seal. It is thus reserved todirect independent claims to these three complexes.

The present invention may be embodied in other forms than thosespecifically disclosed herein without departing from its spirit oressential characteristics. The described embodiments are to beconsidered in all respects only as illustrative and not restrictive, andthe scope of the invention is commensurate with the appended claimsrather than the foregoing description.

LIST OF REFERENCE NUMERALS

-   -   1 pipe section    -   2 lower sealing flap    -   3 closing mechanism    -   4 outlet pipe    -   5 upper filling opening    -   6 upper cover    -   7 locking element    -   8 closing spring    -   9 safety spring    -   10 sliding surface    -   11 cover cap    -   12 additional closing flap    -   13 locking groove    -   14 holding ring    -   15 pivot bearing of the sealing flap    -   16 seal of the sealing flap    -   17 outlet in the pressure region of the sealing flap    -   18 low pressure bypass    -   19 high pressure bypass    -   20 predetermined breaking point    -   21 locking pin    -   22 resilient holding elements    -   23 pipe connection    -   24 holding edge    -   α angle of inclination of the sliding surface relative to the        longitudinal axis of the pipe sec

I claim:
 1. A cap-free closeable neck end for a filler neck of a tank ofa motor vehicle, comprising: a wall for enclosing an inflow region; alower sealing flap; an upper cap-free closing mechanism; and a lowersealing flap, wherein the wall includes a region with a predeterminedbreaking point located between the upper cap-free closing mechanism andthe lower sealing flap.
 2. The cap-free closeable neck end for a fillerneck of a tank of a motor vehicle according to claim 1, wherein theregion comprises a wall thickness that is thinner than other portions ofthe wall.
 3. The cap-free closeable neck end for a filler neck of a tankof a motor vehicle according to claim 2, wherein the region comprises arevolving groove, which is impressed into the wall.